Accelerated versus standard corneal collagen cross-linking in pediatric keratoconus patients: 24 months follow-up results

Purpose

To compare the 24 month visual, refractive, topographic and aberrometric results of the accelerated and standard corneal collagen cross-linking (CXL) in pediatric keratoconus patients.

Synthesis of Oligomeric Calix[4]arene-Crowns as Novel Ionophores for Alkali and Transition Metals

Two different oligomeric calix[4]arene-crowns ( 2b and 3b ) were synthesized ( via ) the condensation reaction of p- tert -butylcalix[4]arene-oxacrown-4 ( 2a ) and p- tert -butylcalix[4]arene-thiacrown-4 ( 3a )(calix[4]arene-crown monomers) with 1,5-dibromopentane. In these oligomerization reactions, it has been found that only three or four calix[4]arene-crowns-4 units have been linked together through alkyl bridges. Their comparative complexing properties with selected alkali and transition metals are reported here. It has been deduced that the selectivity of monomer 2a toward alkali metals has not been reserved, but a pronounced increase in its complexing ability was observed after the oligomerization. However, the selectivity of the monomer 3a toward Cu 2+ , Hg 2+ , and Pb 2+ has also been lost after oligomerization, and it has been found that oligomer 3b is an efficient extractant for the transition metal cations employed in the two-phase extraction systems.     

Bonding strength of oak with different adhesives after humid-water-heat tests

Composite materials manufactured from wood with different adhesives are being used increasingly in the construction of furniture frames and buildings. In this study, it is aimed to describe the effects of adhesives (PVAc, VTKA and UF) on white oak cut tangentially and radially impregnated with Protim WR 230, CCA, and Celcure AC 500 and exposed to humid-water-heat resistance and heating and cooling tests. Impregnation chemicals have decreased the bonding strength, and control samples gave higher bonding strength value. According to the control samples, it can be said that humid-resistance test, water-resistance test, heat-resistance test have decreased the bonding strength. As a result of the tests, white oak cut tangentially and impregnated with Protim WR 230 and bonded with VTKA adhesive can be used as a material in damp condition where the strength is required.     

A rapid method for determination of the origin of meat and meat products based on the extracted fat spectra by using of Raman spectroscopy and chemometric method

Raman spectroscopy and the principal component analysis (PCA) were successfully applied to differentiate the origin of the meat and meat products based on their extracted fat samples in the present study. A total of 132 extracted fat samples that were obtained from different meat species (cattle, sheep, pig, fish, poultry, goat and buffalo) and their salami products were examined based on their Raman measurements. Then, the collected Raman data were analyzed with a four-stage PCA method. Seven meat species and their salami products were successfully differentiated from each other according to their origin. The results of this study showed that the Raman spectroscopy with a chemometric method can be used to detect the origin of the meat species in a very short analysis time (30 s) after fat extraction, without requiring complicated chromatographic, immunologic or genetic methods and instruments as well as trained personnel.     

Optimisation of formulations and infrared–microwave combination baking conditions of chestnut–rice breads

The main objective of this study was to design gluten‐free breads containing chestnut and rice flour and xanthan–guar gum blend to be baked in infrared–microwave combination oven. Response surface methodology (RSM) was used to optimise gluten‐free bread formulations and processing conditions. Weight loss, firmness, specific volume and colour change of the breads were determined. Rice flour mixed with different proportions of chestnut flour and different emulsifier contents were used to prepare breads. The gluten‐free formulations were baked using different upper halogen lamp powers, microwave powers and baking time which were varied from 40% to 80%, 30% to 70% and 9 to 17 min, respectively. Gluten‐free breads and wheat breads baked in conventional oven were used for comparison. Breads containing 46.5% chestnut flour and 0.62% emulsifier and baked using 40% infrared and 30% microwave power for 9 min had statistically comparable quality with conventionally baked ones.     

Results of Pilot Comparisons of National Standards for the Activity of Hydrogen Ions in Aqueous Solutions

Measurement Techniques - The enormous need for support of measurements of the hydrogen index (pH) in various branches of industry and the national economy of Russia make measurement of pH one of...     

Heat pump drying of grape pomace: Performance and product quality analysis

Abstract

Grape is one of the most popular fruits and various types of grape have been cultivated by more than 100 countries around the World. The wine and juice industry produces large quantities of by-product, called grape pomace (GP) as an industrial waste and it consists of skins, seeds, and stems. Various processes such as separation, pressing, drying, and milling are applied to benefit from its health effects. In this study, the seeded black GP Kalecik karas? (Vitis vinifera) was dried in an assisted closed cycle heat pump dryer (HPD) designed for high-moisture products to investigate the drying behaviors of GP. The effects of drying air temperature on bioactive properties and the drying characteristics of GP, and performance of system have discussed. Experiments were carried out at two different temperatures (45 and 50°C) and air velocity of 1.0 m/s. It was seen that increasing temperature decreased the drying time, coefficient of performance of whole system (COP_ws), and specific energy consumption (SEC). The average values of COP_ws for temperatures 45°C and 50°C were calculated as 3.28 and 3.10, respectively. The drying efficiencies (DE) at drying air temperature of 45°C and 50°C ranged from 2 to 12% and from 2 to 15%, respectively. Additionally, result of analysis has indicated that using a HPD at lower temperatures increases performance of system despite of higher energy input. Bioactive properties of dried samples at drying air temperature of 45°C are better than 50°C. The results show that drying the GP at low temperature is more suitable for product quality. For this reason, heat pump may be preferred. It shows that this drying system with higher capacities in the future can be recommended as an alternative technique in terms of energy usage, drying time, and performance of system.